<?php
	function mysubstr($str, $start=0, $length, $charset="utf-8", $suffix=true) {
		if(mb_strlen($str,$charset)<=$length){
			return $str;
		}else{
			if(function_exists("mb_substr"))
        		$slice = mb_substr($str, $start, $length, $charset);
   			 elseif(function_exists('iconv_substr')) {
        		$slice = iconv_substr($str,$start,$length,$charset);
        		if(false === $slice) {
           			 $slice = '';
       			}
    		}else{
		        $re['utf-8']   = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
		        $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";
		        $re['gbk']    = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";
		        $re['big5']   = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";
		        preg_match_all($re[$charset], $str, $match);
		        $slice = join("",array_slice($match[0], $start, $length));
    		}
   				 return $suffix ? $slice.'...' : $slice;
		}
	}
?>